I use bootcamp and dual boot. Using a virtual machine might have too much insulation between the program and hardware causing some of your problems. Not sure. When I get some time I'll install Fusion and see if I get the same issues.

__________________
"Delay is preferable to error" - Thomas Jefferson
"If I have seen further it is by standing on the shoulders of Giants" - Sir Isaac Newton

That is the beginning of the VHD. Probably the easiest way to get to block 0 of the Tivo drive is to use windows disk manager to attach the VHD (make sure you check read only when attaching the VHD) and then use your program to look at block 0.

__________________
"Delay is preferable to error" - Thomas Jefferson
"If I have seen further it is by standing on the shoulders of Giants" - Sir Isaac Newton

Greg-
All your calculations were correct and did get me to block 0. I had some problems initially as the editor I was using (wxHexEditor) was displaying the row offset in decimal not hex. I am familiar with the Intel HEX format (I am an engineer) and expected the offset to be in hex automatically. I couldn't get the offset to display in hex so I had to convert things. I finally realized if I right clicked in the offset column it rotated through the different base systems.

I know I'm sounding long winded but my point is these forums are for helping others; if someone is stuck and wants to understand and do this manually, hopefully they have enough cookie crumbs to do so.

I love HxD, and jmbach uses iBored. Either one is worth a look. I figured it was worth a try with a handle like geekbrain.

Here's the Block 0 from my 746 image. The first two bytes are always 0x1492. The next two are the primary and alternate Root partitions, followed by some text and a bunch of zeroes. I'm not sure if the last 4 bytes mean anything.

If your posts are from a Full or Modified backup you can edit it as necessary and restore it with DvrBARS without changing anything else. If you're feeling adventurous you can edit the disk directly.

That will work. It is essentially what we did for dgorman to fix his. Would suggest that you make a copy of the VHD and play with that when making the edits. Since I don't feel like doing all the calculations, I tend to mount the VHD then use iBored or VxD to edit the mounted VHD. I use iBored to copy and paste block images as it seems easier plus it recognizes various partition Maps and directory structures and displays them in an easy to read format. If you want me to send you the block 0 Greg posted in a hex image, let me know.

__________________
"Delay is preferable to error" - Thomas Jefferson
"If I have seen further it is by standing on the shoulders of Giants" - Sir Isaac Newton

I am thinking of adding a larger drive now that I've got my original drive PROPERLY imaged. I was wondering about the 4K advanced format alignment nonsense. Since DvdBARS handles the drive formatting, is this something you had considered in a future release?

jmbach-
I don't like to confuse 'works' with 'proper' (as in optimized). I picked up the WD10EURX drive (1 TB) and wrote the image from my Premiere (original 320 GB). I have not supersized yet or installed back in the TiVo. I downloaded the G-Parted iso and the drive indicates:

I suspect that all the 4K drives may work, but may experience poor performance and mail ultimately fail prematurely. I welcome any comments from Linux experts out there. I did not see a way to use G-Parted to modify nor did it come up with the partition table I've seen posted. From what I gather a starting sector of 2048 is akin to being 'universal' (Windows, RAID, Linux, 512, 4K).

The 2 tuner premieres are not completely 4k aligned because of the bootstrap partitions being 512 bytes long. The first partition after the APM starts at sector 64 which is 4k aligned. The bootstrap partition starts at a 4k boundary but since it is only 512 bytes in size then next partition does not start at a 4k boundary. The 4 tuner premieres are 4k aligned with the bootstrap partition being 4k in size. I have modded a 2 tuner premiere image to give the bootstrap partition a 4k size and aligned the partitions manually. Haven't seen any difference in performance. Here is another article that explains 4k alignment http://www.ibm.com/developerworks/li...-sector-disks/

__________________
"Delay is preferable to error" - Thomas Jefferson
"If I have seen further it is by standing on the shoulders of Giants" - Sir Isaac Newton

In the long run I think that the actual start of the partitions may be almost meaningless. What other factors are involved like header blocks, inode tables, etc? How often is that part of the disk accessed? How does the drive's internal cache and read-ahead algorithms come into play?

My Premiere XL came from the factory with an AF drive and most of the partitions are not aligned on 4K boundaries. The MFS media partitions are probably the only ones that really matter, and aligning the blocks that the files live on makes a lot more sense to me than worrying about where the header block starts.

When I get into the next phase of development (moving & resizing partitions to expand) my instinct is to just follow TiVo's lead and and lay everything out the same way they do for a drive of the same size, then restore the files to their new home one at a time.

Looking at the 4 tuner TiVos it appears that they adjusted the bootstrap partitions size so that all the following partitions start on a 4k boundary. What that means, I don't know and I have not looked at the inode tables or any other structures to have an idea if it means anything in the end. Based on the article I referenced, all you can do is align the partitions and it is up to the OS to do the rest.

__________________
"Delay is preferable to error" - Thomas Jefferson
"If I have seen further it is by standing on the shoulders of Giants" - Sir Isaac Newton

Yeah, I just don't know for sure at this point and I won't pretend that I do.

With the current generation of AF drives I don't think it really matters but at some point they're going to have to tackle the issue head on. The days when you could assume that a "sector" means 512 bytes are over, but it's still inherent in everything I've seen on TiVos. My best guess is that they they will radically overhaul the filesystem in the next year or two, but if the open source Nazis keep demanding that they release proprietary code it could *blank* the pooch for all of us.